diff --git a/src/Convert/ParamType.hs b/src/Convert/ParamType.hs
index 85be9d6..b9f4931 100644
--- a/src/Convert/ParamType.hs
+++ b/src/Convert/ParamType.hs
@@ -236,6 +236,7 @@ isSimpleType typ =
         IntegerAtom  {} -> True
         NonInteger   {} -> True
         Net          {} -> True
+        Implicit     {} -> True
         Struct   _ fields _ -> all (isSimpleType . fst) fields
         Union    _ fields _ -> all (isSimpleType . fst) fields
         _ -> False